Other packages

The remaining workspace packages are smaller adapters, plugins, runtime helpers, and lint configs. Each is documented briefly here; consult the per-package README and source for specifics.

eslint-config-next

The user-facing ESLint preset. Wraps eslint-plugin-next (see eslint-plugin-next) with eslint-plugin-react, eslint-plugin-react-hooks, and import resolution.

Source: packages/eslint-config-next/. Users add "extends": "next/core-web-vitals" to their .eslintrc.

eslint-plugin-internal

A non-published ESLint plugin used only inside this monorepo. Catches framework-specific anti-patterns: cross-layer imports, the entry-base.ts boundary violations, illegal react-server-dom-webpack/* imports outside entry-base.

Source: packages/eslint-plugin-internal/.

next-bundle-analyzer

Wraps webpack-bundle-analyzer for next build. Exposes a withBundleAnalyzer(config) plugin shape. Activated by setting ANALYZE=true.

Source: packages/next-bundle-analyzer/. The repo also contains a separate @next/bundle-analyzer-ui Storybook for the visualizer UI work.

next-env

Loads .env, .env.local, .env.development, and .env.production files into process.env in a Next.js-friendly precedence order. Uses dotenv and dotenv-expand under the hood.

Source: packages/next-env/index.ts (5 KB). Used by the framework's config loader so that next.config.js itself can read env values.

next-routing

Tools for static routing manifests and route discovery used by the framework's adapter API.

Source: packages/next-routing/src/.

next-playwright

Helpers for using Playwright with Next.js apps. Provides utility functions that wait for hydration, handle App Router navigation, and assert on RSC responses.

Source: packages/next-playwright/.

next-plugin-storybook

Storybook addon for Next.js apps. Sets up Storybook's webpack so it understands next/image, next/link, and the various next/* runtime modules.

Source: packages/next-plugin-storybook/.

next-polyfill-module

Polyfill bundle loaded for browsers that need it. Targets older browsers via the modern/legacy split (the module/nomodule pattern).

Source: packages/next-polyfill-module/.

next-polyfill-nomodule

Companion polyfill bundle loaded by browsers that don't support ES modules.

Source: packages/next-polyfill-nomodule/.

react-refresh-utils

Helpers used by the dev server to make React Refresh (HMR) work cleanly with the App Router and Pages Router. Provides utility functions that wrap react-refresh/runtime calls in a way that survives Server Components.

Source: packages/react-refresh-utils/.

Quick reference

Package	Used by users?	Purpose
eslint-config-next	yes	ESLint preset
eslint-plugin-internal	no	Framework-internal lint rules
next-bundle-analyzer	yes	webpack-bundle-analyzer wrapper
next-env	indirectly	.env loading
next-routing	indirectly	Routing helpers for adapters
next-playwright	yes	Playwright + Next.js helpers
next-plugin-storybook	yes	Storybook integration
next-polyfill-module	indirectly	Modern-browser polyfills
next-polyfill-nomodule	indirectly	Legacy-browser polyfills
react-refresh-utils	indirectly	HMR helpers